Dr Margaret KivelsonWater is a hospitable environment for life real 28k

Friday, 25 August, 2000, 10:43 GMT 11:43 UK

Waterworld on Europa?

Measurements of Europa's magnetic field suggest the hidden presence of a salt-water ocean

Scientists in the United States say the possibility of finding life elsewhere in the Solar System is a step closer.

They have found the most convincing evidence yet that one of the moons of Jupiter - called Europa - has a liquid ocean beneath its icy surface.

The data came from magnetic readings taken by the Galileo spacecraft when it passed close to the moon earlier this year.

The presence of an ocean of liquid water on Europa would strengthen the possibility of finding signs of life there.

Icy sea

Europa is Jupiter's fourth largest moon.

Pictures of its surface show chunks of cracked and broken ice, that seem to be floating on a liquid sea.

Until now, scientists have been unsure whether the ocean still exists today or whether it froze hundreds of thousands of years ago.

New data sent back from the Galileo Spacecraft, which passed close to Europa at the beginning of the year, may contain the answer.

Galileo detected patterns in the moon's internal magnetic field that strongly indicated the presence of a salty ocean.

Life on Europa?

The results were reported in the journal Science by a team of planetary physicists at the University of California, Los Angeles.

They concluded that there could be a salty ocean about seven and a half kilometres below the moon's surface.

However, the scientists cannot tell if the water is definitely salty or not, and they cannot be completely certain that an ocean actually exists.

But the new evidence suggests that if there were an ocean, it would be a good place to look for signs of rudimentary life on Europa.

"It makes it a more interesting possibility to look for signs that there might be life, or there may have been life," Dr Margaret Kivelson, professor of space physics at the University of California, told the BBC.